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Circle A

Research Heterosis Project

About Circle A Ranch

Using Hereford bulls on Angus-based cows will give producers advantages in profitability, cash flow, herd size, and retained female fertility and longevity according to a recently completed study at Circle A Angus Ranch. In fact, when the data was further analyzed for economic emphasis, the results showed an advantage of $514 net per cow over a period of 10 years. That’s a $51 difference per cow per year.

Economic models also predicted that if replacement females are retained over a period of 10 years, Hereford-sired females will generate a 20% advantage in herd size for the same relative cost versus the straight Angus commercial cows because of increased fertility and longevity.


The study, conducted by Circle A Ranch headquartered in Iberia, Mo., in cooperation with the American Hereford Association (AHA), was started in 2007. Mark Akin, Circle A Ranch manager, says, “The female side was what really peaked my interest, because we’ve bred purebred Angus for all these years, and I was curious if the heterosis from the cross would make available a better conception rate for us, and it did.”

To start the project Circle A Ranch AI-bred 600 commercial Angus cows to 10 Hereford bulls with the goal of comparing the best of its Angus herd to the best of the Hereford-Angus cross. The control group included progeny from three proven Angus sires. The average expected progeny differences (EPDs) of the Angus sires would place them in the top 30% of the Angus breed for birth weight and top 20% of the breed for weaning weight. All of the cows and resulting calves were commingled and managed the same.